In a radio communication network in which a group of internet protocols (IPs) is used (hereinafter, referred to as a “radio IP network” as appropriate), so-called Mobile IP is defined in order to improve the mobility of a radio communication device (refer to Non-Patent Document 1, for example).
In Mobile IP, a care of IP address (Care of Address) dynamically assigned to a radio communication device in accordance with a position of the radio communication device is used.
Non-patent literature 1: C. Perkins, “IP Mobility Support (RFC2002),” [online], October 1996, IETF, [retrieved on Mar. 15, 2006], (Internet URL: http://www.ietf.org/rfc/rfc2002.txt)